BOSTON (CBS) – Colton Kulis is a happy and healthy little boy, and that is something his parents Lori and Dave never take for granted.

“Our first one was taken away to soon, and thankfully there was a way for us to have another one,” said Dave.

Their first child was Colby. He was born with Spinal Muscular Atrophy. It is the number one fatal genetic disorder in children under two.

Lori said it was absolutely heartbreaking because there is no cure and no treatment.

Neither Lori nor Dave knew they were a carrier of SMA. Their dreams of having a family were over, until they heard of “Preimplantation Genetic Diagnosis”.

“This gave us really a chance at a life with kids of our own,” said Lori.

Dr. Ian Hardy, the medical director for the Fertility Centers of New England, believes this type of science has improved in recent years. “We have some very delicate equipment that can take a single cell . . . and remove one of those eight cells,” explained Dr. Hardy. “That cell has a nucleus and in that nucleus is the genetic programming for that embryo.”

This process happens just three days after conception. It can detect devastating diseases like Cystic Fibrosis, Fragile X, Tay-Sachs, and Pompeii Disease.

“You will know from which embryo you have the diagnosis,” said Dr. Hardy. “So the embryo that is genetically deemed not to have Cystic Fibrosis would be the choice to put back.”

Although it is an invitro procedure, PGD is increasingly used by couples, like Lori and Dave, who are capable of conceiving naturally.

“I think there were 13 eggs, and number 1, 11, 12, and 13, we can’t use them because they were infected with SMA. I was just amazed they could tell just from one egg,” said Dave.

Traditionally, a pregnant woman would have an amniocentesis at about 16 weeks to check for genetic disorders. But 1/400 procedures has complications, and the results can cause difficult decisions.

“A woman is bonded to the pregnancy, making it even more difficult, and to terminate a pregnancy is not without risk,” added Dr. Hardy.

Dr. Hardy says the industry has strict ethical guidelines to make sure the science isn’t abused in pursuit of so called “Designer Babies.”

For the Kulis family of Methuen, this test changed their lives. “It gave us hope where there was no hope, and it allowed us to live,” said Lori. “We have joy in our lives.”